1. Field of the Invention
The invention relates in general to a flexible printed circuit and a liquid crystal module using the same, and more particularly to a flexible printed circuit having an electrostatic shielding mechanism and a liquid crystal module using the same.
2. Description of the Related Art
Generally, electrostatic discharge (ESD) would damage components inside electronic devices or make the electronic devices malfunction. Therefore, a shielding mechanism is provided in the electronic devices so as to reduce ESD events. A shielding mechanism of a liquid crystal module is disclosed below for exemplification.
Referring to FIG. 1A and FIG. 1B respectively, an iron frame of a conventional liquid crystal module is shown in FIG. 1A, and a side view of the iron frame in FIG. 1A being grounded by contacting a flexible printed circuit is shown in FIG. 1B. The iron frame 10 has a body 11 and an elastic piece 13. A part of the body 11 is removed, so that the elastic piece 13 is bent and protrudes from the body 11. As indicated in FIG. 1 B, an end of the elastic piece 13 is bent once again and grounded by surface contacting a flexible printed circuit 20 in the liquid crystal module 50. Thus, electrostatic charges are discharged from the liquid crystal module 50.
However, as the part of the iron frame 10 is removed (as indicated in FIG. 1A) to form the elastic piece 13, the structural strength of the iron frame 10 is reduced. Referring to FIG. 1C, particles located between the elastic piece and the flexible printed circuit in FIG. 1B are shown. When particles 30, such as dust, are located between the elastic piece 13 and the flexible printed circuit 20, the elastic piece 13 can not exactly contact the flexible printed circuit 20 so as to affect the grounding effect. Furthermore, as the elastic piece 13 is a bent structure and has elasticity, the elastic piece 13 would easily be moved due to the vibration of the liquid crystal module 50. Consequently, the elastic piece 13 can not exactly contact the flexible printed circuit 20 so as to reduce the grounding effect.
In addition, conventionally, the flexible printed circuit and the iron frame are connected by way of soldering to be grounded to discharge electrostatic charges; or a conductive foam is disposed in the liquid crystal module to discharge electrostatic charges. However, soldering not only increases working hours but is normally hard to re-process. The disposition of the conductive foam in the liquid crystal module not only increases the thickness of the liquid crystal module, but also increases working hours and cost. Thus, how to effectively avoid ESD events occurring to the liquid crystal module so as to correspondingly increase the lifespan of the liquid crystal module has become an imminent issue to manufacturers.